Pneumatic apparatus for pumping wells



Aug. 13, 1929. s. B. SMALL PNEUMATIC APPARATUS FOR PUMPING WELLS Filed Oct. 5,1927 3 Sheqts-Sheet 1 ENTOR ATTORNEY G. BfsMALL PNEUMATIC APPARATUS FOR PUMPING WELLS 3 Sheets-Sheet 2 Fi led Oct. 5, i927 INVENTOR MM i ATTORNEY g- 13, 1929- G. B. Sh dALL 1,724,853

PNEUMATIC APPARATUS FOR PUIP ING WELLS Filed Oct. 5. 1927 S'Shets-Sheet a I INVENTOR ATTORNEY Patented Aug. 13, 1929.

UNITED STATESJPATENT OFFICE.

GEORGE B. SMALL, OF TULSA, OKLAHOMA, ASS IGNOR 0F THREE-FOURTHS TO TIDAL OIL COMPANY, OF TULSA, OKLAHOMA, A CORPORATION OF OKLAHOMA.

I PNEUMATIC APPARATUS FOR PUMPING WELLS.

. Application filed October 5, 1927. serial. No. 224,142.

My invention relates to pneumatic apparatus for pumpingzwells and more particularly to displacement of liquid petroleum from wells with air or gas.

surface is commonly effected by mechanical pumping or by delivery of air or gas into the rising column of oil or onto the oil in the well about the tubing to effect flow of the oil to the surface in accordance with well known practices. R 4 A Mechanical pumping is subject to the dis- -advantage of frequent repair and replacement of parts worn by sand and grit in the oil, and the ordinary air lift or ram, as commonly applied, is not always economical and sometimes injurious to the well, particularly when applied to slow heading wells having weak natural pressure.

My invention has for ts-principal objects to socontrol application of air to the well as to avoid interference with heading up of the well and to obviate waste of energy by auto- F niatically limiting supply of artificial pressure for displacing the oil to periods during Vwhich there is an adequate volume of oil for displacement. More particularly my invention relates to apparatusfor automatically admitting a fluid pressure medium to liquid petroleum at the bottom of a well only when a sufiicient amount of liquid has accumulated to perniitits efficient displacement through tubing leading from the Well to a pipe line or storage tank, thereby conserving the arti-- ficial pressure medium and to accomplishment of such result through the instrumentality of valve mechanism controlled by varying pressures resulting from rising and lowering head of oil in the well.

Other obj ects of the invention will become apparent as disclosure of the invention proceeds.

In-the accompanying drawings wherein a preferred form of my apparatus is illusand well in central vertical section, the parts.

appearing as when the displacing flow is interrupted'to permit accumulation of oil in' the Well.

:Fig. 3 is a similar view, illustrating the parts as they appear immediately following operation of the primary valve for admitting I flow for displacing oil from the well. Production of oil from wells having msufficient rock pressure to lift the oil to the.

prising a cylindrical body 10 0f-larger diam;

eter-than the tubing, a reduced neck 11 at its upper end threaded onto the tubing and a closed bottom 12 having a built up boss 13 provided with a port 1 Threaded into the port I l-and depending into the well pocket -is a'strain er pipe 15, and threaded into the port 14 and extending into the trap chamber 16 is anipple 17 carrying a downwardly seating check valve 18,

through which oil admitted to the strainerv pipe is passed to the trap chamber but prevented from return, to thereby effect collection of a charge in the trap.

A T fitting 20 on the tubing above the casing head provides connection for a flow line 21, and extending through a reducing coupling 22 on the T fitting and through the tubing into trap 9 is a conduit 23 for conducting a major flow of artificial pressure medium, hereafter referred to as air, into the trap for release within-oil accumulated in the trap.

The conduit 23 is of sufficiently less diameter than the tubing 8 to provide an annular channel 24 between the conduit and tubing through which oil displaced from the trap is delivered into the flow line 21.

Leading through the casing head andto near the bottom of the casing, exteriorly-of the tubing 23, is a conduit 25 for a minor or pilot flow of air, and opening through the casing head is a vent 26 for relief of air delivered through the pilot line to delay back pressure in the pilot.line until the line is submerged and obviate back pressure on the oil infiowing from the sand.

Referringnow to the mechanism for controlling flow of air to the well for displacing the oil27 and 28 designate master and secondary valve chests, preferably formed as separate castings, and connected by lag bolts 29 extended through a flange-30 on the secondary valve chest into the top of the primary chest, the respective chests having cover plates 31 and 32 secured thereto by bolts 33 and 34.

The assembled chests are supported by a chair 35 from a suitable base, here shown to consist of an accumulatingtank 36 forming part of the apparatus, and to which the seat is attached by bolts 37 extended through feet 38 on the chair legs 39.

The master valve chest 27 includes spaced chambers 40 and 41, having inwardly facing seats 42, 43 connected by a throat 44, and contained within the respective chambers are piston valves 45 46 of differential area rigidly connected by a stem 47, having a reduced shank 48 at one end extended through the valve 45 and forming a shoulder 49 to which the valve is held by a nut 50; the other end of the stemextending through the piston 46 and having a flange 51 towhich the valve is held by a nut 52.

A channel 53 opening laterallythrough the stem and extending through the upper part thereof, provides open communication etween the throat 44 and the part of the chamber 41 above the piston 46, the end of the channel opening into theupper portion of the chamber 41 being restricted as at 54', for a purpose presently described. The lower end of the piston 46 constitutes a valve head 46 having a lower face of less area than the topofthe valve so that when pressure is equalized in chamber 41 andthroat 44 there will be a preponderance of pressure on the piston end tending to head 46 to its seat. 1

Opening laterally from the throat 44 is a port 55 and threaded into said port is a nipple 56 having a reducing coupling 57 for the conduit 23 through which the major flow of air is delivered to the well; the con duit 23 being equipped with a hand valve hold the valve 58 for manually controlling the flow.

O penin through the cover plate 31 at the lower en of the valve chest is a port 59 ..into which is-threaded an L fitting 6O having a reducing coupling 61 for a line 62 leading from a compressor or other source of supply of air under pressures indicated by the cylinder C; the line being provided with a hand valve 63 for manually controlling fiow to the valve mechanism and with a 68 connecting with the piston chamber 67 through a throat 69 and bore 70, the valve chamber having an upwardly facing seat 71 for a valve 72 having a stem 73 extended through the throat and bore into the piston chamber 67 and there connected with a p15;

ton 74 .which-is adapted to reciprocate in chamber 67. A spring 75 seated on the bottom of chamber 67about thestem 7 3 normally supports the piston to retain-the valve 72 closed. a

7 6 designates a bypass or pilot supply line equipped with a filter 77 and orifice fitting 78 and leading from a point in the main supply line 62 between the valve 63 and' piston valve chamber 40 to the piston chamer 67 above .thepiston 74. v

79 designates a branch leading from the pilot line 7 6, between the filter and orifice fitting, to a channel 80 in the valve chest 27 which connects with the bottom of valve chamber 68, and 81 designates a channel in the valve chest 28'leadingfrom the throat 69 to the top of the piston valve chamber 41.

The minor flow or pilot. line 25, heretofore mentioned, leads from the top of the chamber 67 to a point in the Well considerably below the head level of the well, and is equipped with a hand valve 82 and pressure indicator 83.

lVith the parts above mentioned constructed and assembled as described, and assum-" ing the oil in the well to be below its head level (Fig.2), as after preliminary swabbing or following a blowoif'with the present apparatus, air admitted through the line 62 passes in major flow to the chamber '40-and forces the piston valve 45 to its seat, under which conditions no airis admitted to the well in major flow, but is passed in minor flow through the pilot line 76 into chamber 67 above the piston 74 and from said chamber through the line '25, past the manual valve 82, into the well, escaping throng the vent 26 in the casing head.

Oil flowing into the well from the sand within the well about the trap, finally submerging the outlet end of the pilot; line to liquid seal the line. When this sealing occurs'air entering the chamber 67 builds up a pressure suflicient to lower the piston 74 against tension of the spring 75 and pressure of air in chamber 68 against valve 72 and unseat the valve-72. When the valve 72 is unseated a minor flow of air passes from line 76 through branch 79, channel 80, throat'69 and channel 81 into the chamber 41 above the piston 46, first passing into channel 91 to close the valve 95, presently mentioned and then building up a pressure a in chamber 41 equal to the pressure in chamber 40. "When this equalization of pres: sure occurs, the piston 46 being of greater area than the valve 45, the piston and valve are shifted downwardly to unseat the valve 110 rises into the trap past the check valve and a and admit a major flow of air to the well through throat 44, nipple 56 and line 23;

such flowacting to expel oil from the trap 41 through channel 81 being cut off by closing of valve 72 under influence of pressure medium admitted to chamber 67 beneath the piston 74 from the main flow conduit through port 89, chamber'84 and line 99 when the main valve is opened, as presently disclosed, but a balancing supply of air from the ma or flow being admitted to the chamber through the channel 53, in the major flow valve stem.47, as I will now describe.

Also located in the secondary valve chest 28 is a second piston chamber 84, containinga piston 85 including a cage 86 for a downwardly seating check valve 87 for con trolling flow of air from one side of the piston to the other through a port 88, the chamber 84 having connection near its bottom with the lower portion of the chamber 67, through a port 89. Located in the chest 28 below the chamber 84is a valve chamber 90 connecting with the .upper portion of the master piston valve chamber 41. through a channel 91 and with a vent port 92 through a throat 93, a valve seat94 being positioned at the top of the chamber beneath the throat.

95 designates a valve located in chamber 90 and having a stem 96 extended through the throat 93 and a bore 97 in the valve chest into the chamber 84, where it is rigidly connected with the piston 85. Weight of the piston 85 normally retains the valve 95 below its seat so that air may be drained from the major flow chambers and lines through the vent port 92 when supply of major flow is cut off.

Leading from the nipple 56 in the major flow line to a port 98 in the chest 28 and communicating with thelower portion of chamber 84 is a branch 99 through which part of the major flow is diverted to chamber 84 below the piston 85 and then to chamber 67 below piston 74 through port 89, and leading from the top of chamber 84 to storage tank 36 is a linelOO through which the part of the air from the major flow passing through the line 99, chamber 84 and piston 85 -is directed to the storage tank to build up a pressure therein equal to that of themajor flow.

101 designates a return line from the tank 36 to the branch 99 and including a back check valve 102, for relief of the tank through the nipple 56, the master valve throat 44 and vent ports 103 which open from the piston valve chamber 41 above the valve seat 43.

Vhen major flow to the well is established, as heretofore described, a part of the directly flow is diverted through the line 99 to the lower portion of chamber 84, to support the piston 85 and retain valve 95 closed to prevent escape of air from chamber 41 when the minor flow of air is discontinued by closing of the valve 72, the pressureon opposite sides of the piston then being sub stantially equal, but the pressure of major flow air supplied to chamber '41 through channel 53 actingon valve 95 to retain the valve closed. Air continuing to flow into chamber 84 from line 99 lifts the check valve 87 "in piston 85 and passes to the up per part of the chamber 84 and through line 100 to the tank 36' to' build up pressure in the tank equal to that of the major flow. Some of the air admitted to chamber 84 through line 99 is delivered through port 89 into the bottom of chamber" (37, balancing' pressure on the piston and permitting spring to lift the piston and close valve 72, thereby cutting oft minor flow of air to the chamber 41 above the piston valve 46. Cutting off supply of air to chamber 41 by minor flow does not however, afliect the master valve, as a part of the major flow has passed through the channel in the stem 47 to balance pressure on the piston 46 so that it may retain its position.

Air passing to the well trap in major flow under these conditions closes the check valve in the trap and. lifts the oil, as heretofore mentioned. hen the trap has been emptied, air from the major flow escapes through the flow line, reducing pressure in the line 23 below that in the tank 06, and back pressure from the-tank returns piston to its lower position, unseating valve 95 so that pressure on the piston valve 46 is relieved and the master valve returned to initial poage tank until the parts'again assume their original positions.

\Vhen major How of air to the trap is cut off, the standing check valve is relieved andmay open to permit the trap to be recharged with oil from the well, so that the apparatus may repeat its operation when the pilot line again becomes submerged by oil inflowing from the sand. 1

\Vhat I claim and desire to secure by Letters Patent is:

-1. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a line including a valve for conducting pressure medium from said source of supply 'to'the well in major flow for displacing liquid from the well, normally open means controlled by variation of level of liquid in the well for directing a minor flow of fluid from said source of supply to actuating relation with said valve to .open said valve, and means fed from the valve mechanism responsive to pressure of the major flow to close the supply line, a

pilot line for bypassing a minor flow of pressure medium from the source of supply to the Well and to operative relation with the part of said valve mechanism of greater area, secondary valve mechanism normally restraining flow to the differential area valve mechanism and. operative by accumulated pressure resultingfrom sealing of the pilot line by liquid in the well, an accumulator having a f(l "lll1 in open communigat on with the normally closed end of the major flow line, and means responsive to differed" tial pressure in the major flow line and accumulator for relieving the differential valve mechanism to permit said mechanism to close. I

3. In combination with a well having a discharge line, a'source of supply of fiuid pressure medium, a line for conductlng pressure medium from said source of supplytothe Well in major flow, differential area valve.

mechan ism responsive to pressure of the major flow to close the supply line, a pilot line for bypassing a minor flow of pressure medium from the source of supply tothe well and to operativerelation with the part of said valve mechanism of greater area, secondary valve mechanism normally restraining flow to the differential area valve mechanism and operative by accumulated pressure resulting from sealing of the pilot line by liquid in'the well, an accumulator having a feed line in open communication with the normally closed end of the major flow line, means responsive to differential pressure in the major flow line and accumu-l later for relieving the differential valve mechanism to permit said. mechanism to close, and means for Venting the accumulator to reestablish pressure equilibrium between the major flow line and accumulator.

4. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a line leading from said source of supply to the well, including spaced plunger and valve chambers and a connecting throat, plunger and valve memof its connected valve.

5. In combination with a well havirigg a discharge line, a source of supply of uid pressure medium, a line leading from said source of supply to the Well, including spaced plunger and valve chambers and a connecting th'roat,pl unger and valve members of differential area in the respective chambers having a connecting stem extended through said throat, a bypass leading from the supply line to the well and communicating with the plunger chamber, means responsive to accumulated pressure in the bypass resulting from sealingof the bypass by liquid in the well, controlling flow from the bypass to the plunger chamber, and means responsive to drop in pressure in the well for relieving the plunger and permitting closure of its connected valve, the connecting stem having a channel communicating the plunger chamber"and throat to equalize pressures therein when the plunger chamber is closed.

6. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a line leading from said source of supply to the -well,including spaced plunger and valve chambers and a connecting throat, plunger and valve members of differential area in the respective chambers having a connecting stem extended through said throat, a bypass leading from the supply line to the'well and communicating with the plunger chamber, means responsive to accumulated pressure in the bypass resulting from sealing of the bypass by liquid in the well, controlling flow from the bypass to the plunger chamber, and means responsive to drop in pressure in the well for relieving the plunger and permitting closure of its connected valve, "the connecting stem having a channel communicating the" plunger chamher and throat to equalize pressures therein when the plunger chamber is closed, the

channel being restricted to providev differential in supply to and relief from the chamber when the chamber is opened. i

7. In combination with a Well having a discharge line, a sourceof supply of fluid pressure medium, a line leading frond said source of supply to the well, a valve chest in said line including separate valve and plunger chambers having a communicating throat, the plunger chamber having separate supply inlet and vent outlet, a plunger-in the plunger chamber, a valve in the valve 8. In combination with a well having a discharge line, a source of supply of fluid pressure medium,a line leading from said source of supply to the well m'ma or flow,

difi erential area valve mechanism responsive to pressure of the major flow to close the line, a pilot line foi bypassing a minor flow of pressurefluid from the supply line to the well, separate valve mechanisms controlling inlet from the pilot lincto the part of said valve mechanism of greater area and'vent outlet therefrom, said inlet valve mechanism being responsive to pressure accumulated in the bypass by sealing of said bypassby liq uid in the well, to open said inlet, said outlet valve mechanism being responsive to differential in pressure of the major flow to close and open the outlet:

9. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a .line leading from said source of supply to the well in major flow,

differential area valve mechanism responsive to pressure of the majorflow to close the line, a pilot line for bypassing a minor flow of pressure fluid tromthe supply line to the well, separate valve mechanisms controlling inlet from the pilot line to the part of said valve mechanism of greater area and vent outlet therefrom, said inlet valve mechanism being responsive to pressure accumulated in the'bypass by sealing of said bypass by liquid in the well, to open said inlet and to pressure from the major flow to close the inlet, said outlet valve mechanism being responsive to differential in pressure by the major flow to close and open the outlet.

10. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a line leading from said source of supply to the well in major flow, ditlerential area valve mechanism responsive to pressure of the major flow to close the line, a pilot line for bypassing a minor flow of pressure fluid from the supply line to the well, separate valve mechanisms controlling inlet from the pilot line to the part of said valve mechanism ofgreater area and vent outlet therefrom, said inlet valve mechanism being responsive to pressure accumulated in the bypass by sealing of said bypass by liquid in the well, to open said inlet, said outlet valve mechanism being operable primarily by pressure from the by-pass and seconda-- rilybypressure from the major flow to close the outlet, a pressure accumulator fed from the major flow and connected to return pressure medium for opening the outlet valve mechanism in response to drop in pressure of the major flow, and means for venting said accumulator upon return of the differential valve mechanism to normal condition.

11. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a line leading from said source of supply to the well in major flow, differential area valve mechanism in the line responsive to pressure of the fluid to close the line, a pilot line for bypassing a minor flow of said fluid from the supply line to the Well, separate valves controlling inlet from the pilot line to the part of said valve mechanism of greater area and vent outlet therefrom, a plunger operatively connected with said inlet valve and responsive to pressure accumulated in the bypass by sealing of the bypass by liquid in the well, to open said inlet, a plunger operatively connected with said vent outlet valve and responsive to pressure in the major flow line to close said valve, a pressure accumulator, means in said last named plunger including a back check valve responsive to said major flow for permitting supply of the accumulator, and resettable by return of pressure from the accumulator to reopen said outlet valve, and means for venting the major flow line and accumulator upon return of the differential area valve mechanism to normal condition.

'12. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a line leading from said source of supply to the well, a primary valve chest having communicating plunger and valve chambers and vent openings leading from the plunger chamber, connected plunger and valve members of differential area in said chambers, means for supplying a major flow of pressure medium' from the supply source to the valve chamber whereby the valve is normally closed, a well line for receiving said major flow when the valve is open, a secondary valve chesthaving sepa rate inlet and outlet in communication with said plunger chamber and having corresponding communicating plunger chambers, separate valves controlling said inlet and outlet, a plunger in the first of said connecting chambers connected with said inlet valve, means urging said plunger to return the inlet valve a bypass leading through said first communicating plunger chamber to the well and communicating with said inlet whereby a minorfiow of pressure medium is delivered to the differential plunger chamber to. open the major flow valve in response to accumulation of pressure in the bypass induced by sealing of the bypass in the Well, a plunger in the second of said communicating chan e bers connected with the outlet valve and insaid chamber to close the outlet line, and

cluding a back checked valve, an accumulator, means for diverting some of the ma or" flow from the well line to said second plunger Chamber to close the inlet and outlet valves and feed the accumulator through said sechaving an air vent. port in its upper porincommunication with said source of supply arid leading to said discharge line, a minor 'tions and a discharge line having an intake I at the bottomof the well, a source of fluid ressur e medium supply, amajor flow line valve chamber, a valve controlling flow through the inlet line, a plunger chamberinterposed in the minor flow line, a-plunger in said plunger chamber connected with said inlet valve, yieldi'ngly urged to close the inlet valve and responsive to back pressure in'the minor flow line to openlsaidvalve, an soutlet line leading from said-.difierential valveichamber, a valve in said outlet line re sponsive. to pressure in said differential valve chamber to close the outlet line, and means responsive to pressure inthe major flow line controlling said outlet valve.

140 In combination with a closed well,

having an air vent port in its upper por- 'tions anda discharge line having intake at 45 the bottom of the well, a source of fluid pressure medium supply, a major flow line in communication with said source of supply and leading to saiddischarge line, av

-minor flow line in communication with said source of supply andopening to the well below said vent'port, a valve chamber inter-r I posed in the major flow line, a di'fierential area plunger valve. in said chamber normally closed by pressure in them'ajor flow line, {an inlet line leading, from the minor flow line to said valve chamber, a valve controlling flow through the inletline, a plunger chamber interposed in the minor flow line, a plunger in said plunger chamber con-' nected with said v inlet valve, yieldingly urged to close the inlet valve and responsive to back pressure in the minor flow line to open theWalve, and outlet line leading from said diiterential valve chamber, 'a valvein 'said outlet line responsive to pressure in means responsive to normal pressure in the major flow line for retaining the outlet valve closed and to drop in pressure in the major flow line for opening the outlet valve. 15. In combination; with a closed v'vell, having an air vent port in its upper portions and a discharge line having an intake at the bottomof the well, a source of fluid pressure medium supply, a majorfiow'line in communication with said source of supply and .leading to said discharge line, a minor flow line in communication with said source of supply and "opening to the well below said vent port, a valve chamber interposed in the major flow line, a differential area plunger valve in-said chamber normallyclosed by pressure in the major flow line, an inlet line leading from the minor flow line to said valve 'chamber, a valve-controlling flow through the inlet line, afplunger chamber interposed in the minor'flow line,'a plunger in said plunger chamber'conneeted with said inlet valve, yieldingly urged to close theinlet valve and responsive toback pressure in the minor flow line to open said valve, an outlet line leading from said differential valve chamber, a valve in said outlet line re-' sponsive to pressure in said chamber to close the. outlet line, a plunger connectedwith said outlet valve, and means for diverting pressure' medium from the major flow line to said plungers to effect closure of said inlet and oiitlet valves. 1

16. 'In combination with a closed 'well, having aiifair ventport in its upper portions a 'discharge line-havmg an intake at the bottom of the-well, a sourced fluid pressure medium supply, a major flow line in communication with said source of supply 5 --and leading to said discharge line, a minor fio'w line in communication with said source 'of supply and opening to the well below said vent port, a valve chamber interposed in the major fiow line, a differential area plunger valve in said chamber normally closed by pressure in the major flow line, an inlet line leading from the minor flow line to said f valve chamber, a a valve controlling flow through'theinlet line, a plunger chamber interposed in the minor flow line, a plunger in said plunger chamberconnected with said inlet valve, yieldingly urged to close the in.-

let valve and responsive to .backpressure in the minor flow line to open said.valve,]an1zo said outlet valve,rmeans for diverting pres,-

sure medium from the major flow line, to said plungerstoeffect closure o'f's aid inlet and outlet valves, Van' accumulator-incommunication with the major flow line and means for discharging the accumulator onto the second plunger to return the plunger and outlet valve upon drop in pressure in the major flow line.

17. In combination with a well having a closed top provided with a vent port, a discharge line leading from a lower part of the well, a valve chest having spaced valve and piston chambers and a throat connecting said chambers, valve and piston members of different area in the respective chambers, a stem connecting the valve and piston members, having a channel in communication with said throat and leading through the piston member to the piston chamber, inlet and outlet lines in communication with said piston chamber, communicatingprimary and secondary plunger chambers, a plunger in said primary chamber connected with the inlet valve, means. yieldingly urging the plunger to. close the inlet valve, a plunger in the secondary chamber connected with the outlet valve and normally retaining the outlet valve open, means connecting the source of pressure medium supply with the differential valve chamber, a major flow line leading from said throat to near the bottom of the well, a minor fiow line leading from said source of supply through the upper portion of the primary plunger chamber to discharge in the well between the vent port and the outlet of the major flow line, whereby back pressure in the minor flow line may act on the primary plunger to open said inlet valve, a branch leading from the major flow line to the plunger chambers below the plungers,'a-branch leading from the minor flow line to said inlet line to the differential piston chamber, and means for venting the major flow line and the plunger chambers through said valve chest.

18. In combination with a well having a closed top provided with a vent port, a discharge line leading from a lower part of the well, a valve chest having spaced valve and piston chambers and a throat connecting said chambers, valve and piston members of different area in the respective chambers, a stem connecting the valve and piston members, having a channel in communication with said throat and leading through the piston member to the piston chamber, inlet and outlet lines in communication with said piston chamber, communicating primary and secondary plunger chambers, a plunger in said primary chamber connected with the inlet valve, means yieldingly urging the plunger to close the inlet valve, a plunger in the secondary chamber connected with the outlet valve and normally retaining the outlet valve open, means connecting the source of pressure medium supply with the diflterential valve chamber, a major flow line leading from said throat to near the bottom of the well, a minor flow line leading from said source of supply through the upper "portion valve, a branch leading from the major flow line to the plunger chambers below the plungers, a branch leading from the minor ,fiow line to said inlet line to the differential piston chamber, means for venting the major flow line and the plunger chambers through said valve chest, an accumulator in communication with the major flow line and with the upper portion of the secondary plunger chamber 'for returning pressure medium to said chamber to shift the secondary plunger and open the outlet valve upon drop in pressure in the major flow line. I

19. In combination with a well having a closed top provided with a vent port, a discharge line leading from a lower part of the well, a valve chest having spaced valve and piston chambers and a throat connecting said chambers, valve and piston members of dif ferentarea in the respective chambers, a stcmconnecting the valve and piston members, having a channel in communication with said throat and leading through the piston member to the piston chamber, inlet and outlet lines in communication with said piston chamber, communicating primary and secondary plunger chambers, a plungerin said primary chamber connected with the inlet valve, means yieldingly urging the plunger to close the inlet valve, a plunger in the secondary chamber connected with the outlet valve and normally retaining the outlet valve open, an upwardly opening checkvalve in the secondary plunger, means connecting the source of pressure medium supply with the differential valve chamber, a major flow line leading from said throat to near the bottom of the well, a minor flow line leading from said source of supply through the upper portion of the primary plunger chamber to discharge in the well between the vent port and the outlet of the major flow line, whereby back pressure in the minor flow line may act on the primary plunger to open said inlet valve, a branch leading from the major flow line to the plunger chambers below the plungers, a branch leading from the minor flow line to said inlet line to the differential piston chain ber, means for venting the major flow line. and the plungercha-mbers through said valve chest, an ZLCCUIDUlZItOT- in communication with the major flow line and with the upper portion of the secondary plunger chamber for returning pressure medium to said chamber to shift the secondary plunger and open the outlet valve upon drop in pressure inthe major flow line.

20. In combination with a well having a closed top provided-with a vent port, a discharge line leading from alower part of the well, a valve chest having spaced valve and piston chambers and a throat connecting said chambers, valve and piston members of dilferent area in therespective chambers, a stem connecting the valve and piston members, having a channel in communication with said throat and leading through the' piston member to the piston chamber,-

inlet and outlet lines in communicationwith said; piston chamber, communicating pr1- medium supply with the differential valve chamber, a major flow line leading from said throat to near the bottom of the well, a minor flow, line leading from said source of supply through the upper portion of the primaryplunger chamber to discharge in'the .Well between the vent port and the outlet of the major flow line, whereby back pressure in the minor flow line may act on the primary plunger to open said inlet valve, a branch leading from the major flow line to the plunger chambers below the plungers, a branch leading from the minor flow line to said inlet line to the difierential piston chamber, means for venting the major flow line and the plunger chambers through said valve chest, an accumulator in communication with the upper portion of the secondary plunger chamber for returning pressure medium to said chamber to shift the secondary plunger and open the outlet valve upon drop in pressurein the major flow line.

21. In combination with "a well and a' i source of supply oftfluid pressure medium,

a trap in said well having a discharge line, a major flow line leading from said source of supply to the trap, a differential pressure valve controlling said line and normally closed by pressure in the line, a minor flow line leadingfrom said source of.sup ply to the well and adapted for liquid sealing by fluid in the well, a branch for directing pressure medium to-operative relation with the differential valve, and means responsive to differential pressures in the major and minor flow lines controlling said branch. v

22. In combination with a well and a sourceof supply of fluid pressure medium, a trap in said well having a discharge line, a major flow line leading from said source of supply to the trap, a differential pressure valve'controlling said line and normal- 1 closed'by pressure in the line, a minor flbw line leading from'said source of supply to the well and adapted for liquid sealing by fluid in the Well, a branch for directing pressure medium to operative rela- 'tion with the differential valve, and means responsive to rise in pressure in the'minor flow line foropening said branch and'to difference in pressure between the major and minor flow lines for closing the branch.

23. In combination with a well having a discharge line, a source of supply of fluid pressure medium having a major flow line leading to the well, a pressure chamber, a pressure actuated valve normally closing the supplyline and having a piston in the'pressure chamber, a line for conducting pressure medium from said source of supply to the j pressure chamber, including a valvejcham her a secondar iston chamber a second ary piston dividingsaid secondary chamher into inner and outer port ons, a secondary valve in said -valve chamber con-Q nected with said secondary piston and cons trolling said conducting line, means for conductlng pressure medium' from saidsource of supply to the outer portion of the I secondary piston chamber, and lines leading respectively from outer and inner portions of the secondary piston chamber to the well and major flow line for opening and-closing the conducting line in response to varying differential pressures in the lines leading to the well. I i

24. In combination with a well having a discharge line, a source of supply of fluid pressure medium having a primary line leading, to the well, a pressure controlled valve normally closing the supply line, a secondary line leading from the source of supply to the well, means responsive to rise in level of'liquid in the well for conducting pressure medium to controlling relation with said valve to open the valve, and means responsive to difference in pressure in the primary and secondary lines for interrupting flow of pressure medium to controlling relation with the valve.

. 25. In combination with a well having a discharge line, a source of supply'of fluid pressure medium having major and minor flow lines leading to the well, a pressure controlled valve normally closing-the major flow line, a line for conducting pressure mary valve mechanism controlling flow through the primary conduit, secondary valve mechanism responsive to variation in effective forces in the secondary conduit con trolling the primary valve mechanism, to effect opening of said valve mechanism, and means for enabling closure of said primary valve mechanism.

27. In combination with a well having a discharge line, a source of supply of fluid pressure medium having a primary conduit leading to the well and a secondary conduit leading into the well independently of the primary conduit and adapted for liquid sealing by fluid in the well, a pressure operated valve normally closing the primary conduit under influence of pressure in the primary conduit, means for conducting pressure medium to contra-relation with the valve for opening the valve, means responsive to variation in pressure in the secondary conduit controlling flow through said conducting means, and means for enabling closure of the valve.

28. In combination with a well having a discharge line, a source of supply of fluid pressure medium having a primary conduit leading to the well, a secondary conduit connected with said source of supply and adapted to be sealed by liquid rising inthe well, a differential area valve normally closing the primary conduit, means responsive to variation in pressure in the secondary conduit for admitting pressure medium to the valve to open the valve, and means for enabling closure of the valve. I

29. In combination with a well having a discharge line, a source of supply of fluid pressure medium having a primary conduit leading to the well, a valve normally closing the primary conduit, a line for delivering pressure medium to contra-relation with the valve for opening the valve, a secondary valve in said delivery line, a secondary conduit leading from said source of supply to the well, means responsive to variation in pressure in the secondary conduit for actuating the secondary valve, and meansior enabling closure of the primary conduit valve.

30. In combination with a well having a discharge line, a source of supply of fluid pressure medium having a primary conduit leading to the well, a valve normally closing said conduit, a secondary conduit leading from said source of supply to the well independently of the primary conduit and arranged to be sealed by liquid rising in the well, valve mechanism operable. by pressure fluid medium trapped in the secondary conduit controlling opening of the rimary conduit valve, and means for enabling closure of the valve.

31. In combination with a well having a discharge line, a source of: supply of fluid pressure medium having a primary conduit leading to the well, valve mechanism controlling flow through said conduit including piston and valve chambers, connected, differential-area piston and valve members in said chambers responsive to pressure in the primary conduit for closing the valve, a line for conductingpressure medium to the pieton chamber for opening the valve, a secondary valve controlling flow through said line, a secondary conduit leading from said source of supply into the well and adapted for liquid sealing by fluid in the well, means responsive to variation in pressure in the secondary conduit for operating the second ary valve, and meansfor enabling closure of the piston valve mechanism.

32. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a valve housing including spaced chambers having oppositely facing seats and a connecting throat, a spool valve having heads of differential area located in the respective chambers, a primary conduit including a primary section leading from the source of supply to the chamber for the head of lesser area and section leading from said throat to the well, means for conducting pressure medium from said source of supply to the chamber for the head of greater area, a secondary conduit leading from said source of supply into the well and adapted tobe liquid sealed by fluid in the well, means responsive to variation in pressure in the secondary conduit controlling flow of pressure medium to the chamber for the valve ,head of greater area, and means for enabling closure of the spool valve.

33. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a valve housing including spaced chambers having oppositely facing seats and a connecting throat, a spool valve having heads of differential area located in the respective chambers, a primary conduit including a primary section leading from the source of supply to the chamber for the head of lesser area and a section leading from said throat to the well, means for conducting pressure medium from said source of supply to the chamber for the head of greater area, a secondary conduit leading from said source of supply into the well and adapted to be liquid sealed by fluid in the well, means responsive to variation in pressure in the secondary conduit controlling flow of pressure medium to thechamber for the valve head of greater area, said last-named chamber having a vent for relieving the section of the primary conduit leading to the well, and means controlling said vent.

34. In combination with a well having a discharge line, valve chambers having a connecting throat and oppositely facing seats at the ends of the throat, a spool valve having heads of differential area in the respective chambers and adapted for seating on the respective seats, a source of supply of fluid pressure medium having a conduit section leading to the chamber for the valve head of lesser area whereby said head is normally re-' tained on its seat by pressure of the medium supplied through said section, a conduit section communicating with said throat and leading to the well, a secondary valve chamber having a line of communication to the chamber for the spool valve head of greater area, a piston chamber, a piston in said chamdischarge line, valve chambers having a connecting throat and oppositely facing seats at the ends of the throat, a spool valve having heads of differential area in the respective I chambers and adapted for seating on the respective seats, a source of supply of fluid pressure medium having a conduit section leading to the chamber for the valve head of lesser area whereby said head is normally retained on its seat by pressure of the medium suppliedthrough said section, a conduit section communicating with' said throat and leading to the well, a secondary valve cham-' ber having a line of communication to the chamber for the spool valve head of'greater area, a piston chamber, a piston in said chamber, a valve in the secondary valve chamber connected with said piston and normally closing said line of communication, means for conducting fluid pressure medium to said secondary-valve chamber and to the upper portion of said piston chamber, a line leading from the upper portion of said piston chamber into the well and adapted for liquid sealinglby fluid in the well, means'normally urging said piston to close the secondary valve, and means for enabling closure of the spool valve.

36. In combination with a well having a discharge-line and a source of supply of fluid pressure medium, primary piston and valve chambers; -ahigh pressure line leading from the source of supply through the primary valve chamber to the well, connected primary piston and. valve members respectively 10- catedin said chambers, a by-pass leading from the high pressure line to the primary piston chamber, a low pressure line leading from said source of supply to the well, a

secondary piston valve responsive to vari fllJlOn in pressure in the low pressure line controlling flow through said by-pass, and means for enabling closure of the primary valve.

37. In combination with a well having a discharge line and a source of supply of fluid pressure medium, primary piston and valve chambers, ahigh pressure line leading from the source of supply through the primaryvalve chamber to'the well, connected primary piston and valve members respectively located in said chambers, a by-pass leading from the hi h pressureline to the primary piston cham er, a low pressure line leading from said source of supply to the well, connected secondary piston and valve members having chambers interposed in the low pres-- sure line and by-pass respectively, responsive to variation in line for contro ing flow through said bypass, and means for enabling closure of the primary valve.

38. In combination with a Well havinga discharge line and a source of supplyof fluid pressure medium, connected primary piston and" valve members having connected cham- "bers provided with opposed valve seats, the

piston having a valve portion co-operative with-one of said seats, a high pressureline leading from the source ofsupply to the well through said valve chamberfa vent for saidline normally open through the seat for the valve portion of said piston, a by-pass from the high pressure line to the piston chamber, including a secondary valve chamber, a low pressure line leading from said source'ofsupply to the well, a secondary pis ton chamber interposed in the low pressure line, connected secondary piston and valve members in the respective secondary cham- .bers, responsive tovariation in pressure in the low pressure line, means yieldingly urgiing said secondary members to close said by-pass, and means for enabling closure of the primary valve.

39. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a conduit leading from said source of supply to the well, a valve normally closing the conduit under influence of pressure medium therein, means in cludin'g a normally closed conduit for supplying pressure medium to contra-relation with the valve to open the valve, means for opening said conduit, and means responsive to variation in pressure in the well for releasing said supply to permit the valve to close.

40. In combination with a wellhaving a,

pressure in the low pressure in the primary and secondary conduits to open the supply line, and to pressure in the primary line to close the supply line, and means for enabling closure of the primary valve mechanism. a a

41. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a primary conduit leading from the source of supply to the well, a normally closed valve controlling flow through the primary conduit, a line for supplying pressure medium from the source of supply to open said valve, a secondary conduit leading from the source of supply to the well and adapted for liquid sealintg by fluid in the well, means responsive to di ference in pressures in the primary and secondary conduits for opening said supply line and to pressure in the primary conduit for closing said line, and means for enablin closure of the primary valve.

42. In combination with a well having a discharge line, a source of supply of fluid pressure medium, a primary conduit leading from the source of supply to the well, a normally closed pressure responsivevalve con trolling flow through the primary conduit,

a line for'supplying pressure medium from' the source of supply to open said valve, said supply line having a "relief vent, means con-- trolling flow through said supply line, and

. means responsive to difference in pressures in said supply line and in the well foropening the vent to permit said valve to close.

43. In combination with a well having a discharge line, asource of supply of fluid pressure medium, a primary conduit leading from the source of supply to the well, a

normally closed pressure responsive valve controlling flow through the primary conduit, a line for supplying pressure medium from the source of supply to open the valve,

' said supply line having a relief vent, means controlling flow through said supply line,

a and means responsive to difference in pressures in said primary conduit and supply line for closing and opening the vent.

44. In combination with a well having a discharge line and a source of supply of fluid pressure medium, differential pressure major and minorflow lines leading from said source of supply to the well, and means responsive to change in differential of effective forces in the major and minor flow lines controlling flow through the major flow line.

45. In combination with a well having a discharge line and a source of supply of fluid pressure medium, differential pressure major and minor flow lines leading from major and minor flow lines leading from i said source of supply to the well, means including a piston valvecontrolling flow through the major flow line, a line leading from said source of supply to the piston side of said valve, and valve mechanism responsive to change in differential of effective forces inthe major and minor flow, lines controlling flow through said piston line.

- 47. In combination with a well having a discharge line and a source of supply of fluid pressure medium, d-ifl'erential pressure major and minor flow lines leadingfrom said source of supply to the we1l,'means including a piston valve controlling flow through the major flow line, a line leading from said source of supply to the piston side of said valve, and valvemechanism responsive to change in differential of effective forces in the major and minor flow lines induced by liquid sealing of the minor flow through said piston line.

48. In combination with a well having a discharge line, adapted for submergenceby fluid rising in'the well, a primary line for conducting fluid pressure medium to said well fluid for displacing the same through the discharge line, primary valve mechanism for controlling flow through said primary line, an auxiliary line for conducting fluid pressure medium to actuating relation with said primary valve mechanism to open the primary line, means responswe to change in pressure induced by rise of level of fluid in the well controlling flow through the auxiliary line, and means responsive to change in pressure induced by entry of pressure medium to the discharge line behind displaced well fluid,- for releasing pressure medium from actuating relation with the primary valve mechanism to permit closure of the primary line.

In testimony whereof I aflix my signature.

GEORGE E. SMALL. 

